Used as a catalyst in hydrodesulfurization processes to remove sulfur from crude oil and natural gas, improving fuel quality and reducing sulfur emissions. Employed in electroplating baths to deposit nickel sulfide films for electronic and optical devices. Applied in the synthesis of nanomaterials for solar cells and battery electrodes due to its semiconductor properties. Investigated for use in photocatalytic water splitting to produce hydrogen under visible light. Also utilized in pigments for ceramics and glass, providing black or dark gray colors.